Blow plate for core blowers



June 8, 1965 J- P. CUMMINGS ETAL 3,187,391

BLOW PLATE FOR CORE BLOWERS 2 Sheets-Sheet 1 Filed Nov. 19, 1962 I s jasgokp 624m 8, 1965 J. P. CUMMINGS ETAL 3,187,391

BLOW PLATE FOR CORE BLOWERS Filed Ndv. 19, 1962 2 Sheets-Sheet 2 United States Patent 3,187,391 BLOW PLATE FOR CORE BLOWERS Joseph P. Cummings and Lee R. Rice, Indianapolis, Ind.,

assignors to International Harvester Company, Chicago, Ill., a corporation of New Jersey Filed Nov. 19, 1962, Ser. No. 238,41 5 Claims. ((11. 22-10) This invention relates in general to foundry apparatus, and more in particular to a new and improved blow plate [for use with a core blowing machine.

In core blowing apparatus it is conventional to secure a blow plate to the bottom of the sand magazine to retain the sand in the magazine when it moves back and forth for refi-ll, yet which freely allows'the sand to flow therefrom when a blast of air is applied thereto. Prior art devices have used a cast grid-like structure, however, due to the inherent thickness of the individual bars, the flow of sand from the magazine has been impeded. Further- I more, the thickness of the bars,particularly at their intersection, has often been so great as to substantially cover a blow hole in the core box, which often results in an improperlyblown. core. Recognizing the problems encountered in the cast grid typeof structure, those skilled in the art have attempted to obviate the difliculties encountered therewith'by providing a blow plate having a plurality of holes. drilled therethrough as close as possible to one another without 1 weakening the plate; This type of structure has also proven unsatisfactory in that a triangular-like restriction is formed between adjacent holes, and whenever a blow hole is disposed under the pose of which will hereinafter become apparent. The upper surface of the sand within magazine 11 is exposed to a source of pressurized air, not shown, which is periodically applied to the magazine through inlet 14 to eject the sand therefrom.

Associated with core blowing machine 10 is a core box 15 into which the sand from magazine 11 is forced to form the desired cores. A lid member 16 is mounted upon the upper surface of core box 15, and is provided with. a plurality of openings 17 which are adapted to admit the sand into the interior of the core box.

A blow plate indicated generally at 20 is provided to retain the sand within magazine 11 during all non-blowing operations. Blow plate 20 includes a solid outer portion 21, substantially rectangular in plan View in the preferred' embodiment, the dimensions of which are substantially identical with the lower surface of magazine 11.

Blowplate portion 21 is provided with a plurality of countersunk holes 22, which are disposed in substantial vertical alignment with the holes 13 in magazine flange 1'2, and are adapted to receive aplurality of bolts, not shown, to 'removably secure the blow plate to the bottom of magazine 11. V Blow plate 20 further includes a grid-like central area indicated generally at 23. Grid 23 includes a plurality of equally spaced-apart longitudinally andtransversely extending thin gage strap members 24. Both the longirestriction, a defective core is produced. The general purpose of the present invention is therefore to provide a device which overcomes the difiiculties encountered in the use of prior art devices, yet which is inexpensive to manufacture and easy to assemble.

An object of the present invention is the provision of a blow plate which will enable a core blowing machine to consistently and satisfactorily produce a high quality core.

Another object of the invention is to provide a blow plate which will effectively retain sand in the hand magazine during non-blowing operations, yet which presents a minimum restriction to allow the sand to flow freely during the core blowing operation.

A further object of the invention is the provision of a blow plate structure which will prevent the undue wastage of sand.

Other objects and advantages of the invention will hereinafter become more fully apparent from the following description of the annexed drawing, which illustrates a preferred embodiment, and wherein:

FIG. 1 is an exploded perspective view of a conventional core blowing machine having the blow plate out the present invention associated therewith:

FIG. 2 is a partial plan View of the blow plate;

FIG. 3 is a section View taken along the line 3-3 of FIG. 2;

FIG. 4 is a fragmentary detail view of one of the individual grid straps;

FIG. 5 is an enlarged plan view showing the details of construction of the grid straps; and

'FIG. 6 is an elevational view of the structure set forth in FIG. 5. 7

Referring now to the drawings, wherein like reference characters designate like or corresponding parts throughout the several views, a conventional core blowing machine is indicated in its entirety by reference number 10 in FIG. 1. Core blower 10 includes a magazine member 11 which is adapted to hold a supply of sand. Magazine 111 is provided at its lower edge with a peripherally extending flange 12 having a plurality of apertures 13, the purtudinally and transversely extending strap members 24 contain. a' plurality of equally spaced-apart cut out or notched portions 25. It will be readily understood that thealignedcutout portions on the transversely extending straps 24 will define a plurality of equally spaced-apart longitudinally extending grooves, While the aligned cutout portions 25 on the longitudinally extending straps 24 will define a plurality of transversely extending grooves. The grid structure may be assembled by either aligning the longitudinally extending strap members and placing the transversely extending strap members in the resulting grooves formed by the cutout portions 25 in the longitudinally extending strap members, or by aligning the transversely extending members and placing the longitudinally extending members in the grooves formed by the cutout portions 25 in the transversely extending strap members. As can be readily understood, the resulting grid structure will have a thickness which is substantially identical to the thickness of the individual strap members. It will be observed that because of the substantially equal spacing of cutout portions 25, the resulting grid will have a checkerboard configuration, and a plurality of square voids will be produced between adjacent pairs of transverse and longitudinally extending strap members. To complete the grid assembly, a solid band 27 is disposed around the periphery of the grid, and a small drop of weld material 28 is deposited on both sides at each intersection of every transverse and longitudinal strap member. The composite grid structure 23 is then secured within core plate shell portion 221 by any conventional means, such as by pinning or by welding. It should be apparent that grid 23 presents an area of minimum exposure to the It has been found that a grid constructed of steel strapping having an approximate thickness of .028 of an inch, a

, height of .75 of an inch, and wherein the cutout portions were formed at A; of an inch intervals, has functioned in Patented J one 8, 1965 9 a most effective manner to consistently produce high quality cores. During non-blowing operations, such a grid has eifectively restrained the sand from flowing therethrough due to the cohesion of the individual sand particles themselves and the adhesion of the sand particles to the strap members.

It should be understood, of course, that the foregoing disclosure relates to only a preferred embodiment of the invention, and that numerous modifications or alterations may be made therein without departing from the spirit and the scope of the invention as set forth in the appended claims.

What is claimed is:

1. For use with a core blowing machine including a sand magazine, a source of pressurized air associated therewith, and a core box positioned below said magazine to receive sand therefrom, said core box having a plurality of blow openings, a core plate comprising: a grid, said grid including a plurality of spaced-apart longitudinally extending thin gage strap members, said grid further including a plurality of spaced-apart transversely extending thin gage strap members, the intersect-ion of said longitudinal and transverse strap members presenting an area having side dimensions which are substantially equal to thewidth of said longitudinal and transverse strap members, and support means operatively associated with said grid and adapted to secure said grid between said magazine and said core box over said openings.

2. For use with a core blowing machine including a sand magazine, a source of pressurized air associated therewith, and a core box positioned below said magazine to receive sand therefrom, said core box having a plurality of blow openings, a core plate comprising: a grid, said grid including a first set of generally equally spaced-apart thin gage strap members, each of said strap members containing a plurality of substantially equally spaced-apart cutout portions, cutout portions on adjacent strap members being aligned and defining a plurality of g grooves extending across said grid at substantially right angles to said first set of strap members, a second set of thin gage strap members positioned within said grooves, means securing said first and second sets of strap members together at their intersection, said first and second sets of strap members defining therdbetween a plurality of substantially square void areas, and support means operatively associated with said grid and adapted to secure said grid to and between said magazine and said core box over said openings.

'3. The invention set forth in claim 2 wherein each of said second set of strap members is provided with a plurality of equally spaced-apart cutout portions, the distance between the cutout portions on said second set of strap members corresponding to the distance between the cutout portion in said first set of strap members, the cutout portions 011 said first strap members being positioned in interlocking relation with the cutout portions on said second set of strap members.

-4. The invention set forth in claim 3 wherein each cutout portion extends substantially half-way through its strap member so that the resulting grid structure has a height generally equal to the height of each individual strap member.

5. The invention set forth in claim 3 wherein the width of each cutout portion is substantially equal to the thickness of said strap members. 1

References Cited by the Examiner UNITED STATES PATENTS 1,533,220 4/ 25 Campbell 2236 FOREIGN PATENTS 987,5 32 4/ 51 France.

MICHAEL V. BRINDISI, Primary Examiner.

MARCUS U. LYONS, Examiner. 

1. FOR USE WITH A CORE BLOWING MACHINE INCLUDING A SAND MAGAZINE, A SOURCE OF PRESSURIZED AIR ASSOCIATED THEREWITH, AND A CORE BOX POSITIONED BELOW SAID MAGAZINE TO RECEIVE SAND THEREFROM, SAID CORE BOX HAVING A PLURALITY OF BLOW OPENINGS, A CORE PLATE COMPRISING: GRID FURTHER GRID INCLUDING A PLURALITY OF SPACED-APART LONGITUDINALLY EXTENDING THIN GAGE STRAP MEMBERS, SAID GRIP FURTHER INCLUDING A PLURALITY OF SPACED-APART TRANSVERSELY EXTENDING THIN GAGE STRAP MEMBERS, THE INTERSECTION OF SAID LONGITUDINAL AND TRANSVERSE STRAP MEMBERS PRESENTING AN AREA HAVING SIDE DIMENSIONS WHICH ARE SUBSTANTIALLY EQUAL TO THE WIDTH OF SAID LONGITUDINAL AND TRANSVERSE STRAP MEMBERS, AND SUPPORT MEANS OPERATIVELY ASSOCIATED WITH SAID GRID AND ADAPTED TO SECURE SAID GRIP BETWEEN SAID MAGAZINE AND SAID CORE BOX OVER SAID OPENINGS. 